Drying and cooling apparatus



Nov. 29, 1938.

E. A LTENKIRCH DRYING AND COOLING APPARATUS Filed Feb. 17, 1954 PatentedNov. 29, 1938 PATENT oFFicE l2,138,684 DRYING AND COOLING APPARATUSEdmund Altenkirch, Neuenhagen, near Berlin, Germany Application February17, 1934, Serial No. 711,673 In Germany February 24, 1933 19 Claims.

This invention relates to air conditioning apparatus and moreparticularly for means for cooling and drying air.

It is well known that silica gel, charcoal, certain kinds of wood, andother substances have the properties of absorbing water or otherrefrigerating uids at one temperature and discharging the water or uidsat a higher temperature. It is also known that certain liquids such l@as sulphuric acid, lye solution, calciiun chloride solution, etc., havethe property of absorbingmeans for removing water from air by aninexpensive and simple apparatus.

It is still another object of the invention to provide air conditioningapparatus which may be operated at low temperatures and thus utilize theheat of the sun for operating it.

3 Other objects and advantages reside in certain novel features of thearrangement and construction of parts as will be apparent from thefollowing description taken in connection with the accompanying drawingin which:

Figure 1 is a fragmentary cross-sectional view of an apparatus forremoving moisture from the atmosphere or from other gases which may .becirculated through it, the apparatus illustrating one embodiment of theinvention, and

Figure 2 is a fragmentary view of a dwelling house with the wallsshownin cross-section and with another embodiment of the inventionincorporated therein which is adapted to dry and cool the air inthevhouse.

f Referring to the drawing in detail and first to the embodiment of theinvention shown in Figure 1, the apparatus is shown as consisting of avertically extending rectangular structure designated at i@ andconsisting chieflyv of insulating 5G material, the east and west wallsof which have vertically extending rectangular chambers as indicated atil and I2.

Centrally located in the structure I0 is a third vertically extendingchamber which may be of 55 any shape, either rectangular or circular asshown nected to the outlet pipe 26.

at I3. This chamber i3 is connected at the top to chimney I4 and, at thebottom to an opening I5, the opening I5 connecting the .chamber I3 tothe atmosphere on the north side of the structure. An electric motor I6and a fan I'I are located in the lower portion of the chamber I3 andvprovide means for forcing air upwardly through the chamber I3, the airentering through tige opening I5 and leaving through the chimney lo Toprevent the sun from heating the insulating structure I0, a roof i8 maybe proyided and air may be circulated thereunder if desired.

Each of the east and west chambers II and I2 constitutes `anabsorber-generator and is provided witha number of pans or cup-shapedbaffles, those in the east chamber il being' designated i9, and those inthe west chamber I2 being designated 26. These cups or pansare' partlyfilled with a substance such as silica gel, or cal- 2o cium chloridesolution, or other substance adapted to absorb water out of theatmosphere if maintained at reasonably low temperatures.' VIf designedfor use with solid absorbents, the pans are preferably perforated.staggered between the cups i9 and 2li are a number of baiiie platesindicated at 2i which serve to direct air over lthe pans and in contactwith the absorbing substance thereon as air circulates through theapparatus.

The upper ends of the chambers il and I2 30 v are connected together bymeans of the gas conduit 22. This gas conduit extends into the cham'-bei,` i3 in which it passes downwardly to form a U- bend 23, which isconnected by means of the T- connection 2d with a pipe 25. The pipe 25serves 35 as a water-reservoir and has its lower end con- The pipe 26may be provided with a faucet, or may drain into a suitable receptacleto collect water supplied to the reservoir 25 by the apparatus. 40

The lower end of each of the chambers II and i2 are connected to theatmphere by means of the gas conduits 21 and 28. Screens or filters (notshown) may be provided in the conduits 21 and 28, to prevent theentrance of insects into 45 the apparatus. If desired the conduits 21and 28 may be connected to a suitable air pump or a fan for forcing adraft of air through the apparatus.

Since the outer walls of the east and west chambers Il and l2 are madeof metal, it will be seen that on a sunny day, heat will be transferredfrom the sun to the air and to the absorbing ma- 'terial in the eastchamber il in the morning and to the air and the absorbing material inthe west hereinafter.

chamber i2 in the afternoon.. Other heating devices might also beemployed in this apparatus but are not illustrated for the sake ofsimplicity herein but are shown in the arrangement of Figure 2. It istol be understood, however, that the arrangement of Figure l is notlimited to the use of the heat from the sun alone to operate it.

Assuming that the plates or trays I9 and 2Il of the apparatus of Figurel are lled with' silica gel the apparatus may be operated to removemoisture from air as follows: In the morning the sun will .shine uponthe outer wall of the east chamber Il while .the west chamber I2 will bein the shade and at a lower temperature. This will cause the air in theeast chamber Ill to have lower density, and, assuming that the pipes 21and 28 are open to the atmosphere air will rise in the east chamber Il,pass through the conduit 22, which will be maintained at a lowertemperature than thatof the chamber Il by the air current set up in thechamber I3. From the conduit 22 the airwill ow downwardly through thewest chamber I2 and leave the apparatus through the pipe 28. The airwill now in this direction all morning and since the east chamber II isquite warm moisture will be'given up from the silica gel on the pans I9to the air. This air having a higher moisture content as it enters thegas'conduit 22 than the air entering through the conduit 21, will dropsome of its moisture as-it is reduced to the temperature of theatmosphere in the inner chamber I3 of the apparatus. During the initialcycle of the apparatus it may be that there will be little or nocondensation in the pipe 22 but as the cycle is repeated condensation inthis pipe Will increase -as will be apparent from the description Evenduring the starting cycle, however, the air entering the conduit 22 willhave a higher moisture content .than that entering the chamber I lthrough the pipe 21.

As the air passes downwardly through the west chamber I2 its moisturecontent will be reduced due to the absorption of moisture by the silica.

gelI on the trays 20 and thel air leaving the apparatus through theconduit 28 will have a lower moisture content than that entering theapparatus through the conduit'21, the difference being that which hascondensed lin the conduit 22.

As the sun passes the` meridian it willv not shine on either the east oron the west walls of the apparatus and air ,circulation therethroughwill cease temporarily. In the afternoon the sun will shine on the westchamber. I2. Air will then circulate through the apparatus entering inthrough the gas pipe 28 passing upwardly through the west chamber I2through the gas conduit 22 and downwardly through the east chamber II.The silica gel in the west chamber I2 which became highly saturated withwater vapor during the morning, now gives up its moisture to the air andas the temperature of the air in pipe 22 is reduced in chamber I3, alarge part oi' the water vaporv condenses in the conduit 22 and collectsin the reservoir 25.

Likewise the air which ows from pipe 22 into the east chamber I I nowhas a higher water vapo` pressure than that which enters the westchamber I2 in the morning and the silica gel on the trays I9 become evenmore saturated than the gel in the trays v20 did in the morning.Nevertheless the air leaving the apparatus through the conduit 21 is ina dryer state than that entering the apparatus through the -conduit 28.From then on, if the quantity of gel in the apparatus and the quantityof air owing therethrough are properly proportioned, water will beretained in the apparatus at each period of operation.

Since heat is being discharged into the air in the inner chamber I3 'ofthe apparatus a natural draft may be created which will be suicient tocool the gas conduit 22 and cause condensation therein. In this way theapparatus could be operated without the use of moving parts. The use ofa motor driven fan as shown in I'I is preferable, however, in that itmaintains the gas conduit 22 at a lower temperature.

It will be seen from the above description that means has been providedfor using the heat of the sun for obtaining a supply of water from theair. It is also apparent that the apparatus may be operated to cause theheat of the sun to dry air for bringing comfort to human beings or forother purposes and that the drying process may take place without theuse of moving parts. The pipes 21 and`28 may be connected to the room inwhich it is desired to maintain air at a low relative humidity and theconduits 21 and 23 may be connected through various known valve systemsand to blowers or fans in such a way that air may be nearly continuouslysupplied to a chamber at a relative humidity lower than that of the airentering the apparatus. Conversely, assumingl that it is desired toraise the humidity in a room, the conduit 22 might be connected to theroom in such a way that it would add moisture yto the air. 'I'hus ifchamber I3 were sealed from the atmosphere at the top and bottom, andthe pipe 22 were cut oi at the point of entrance into chamber I3, thehumidity of the air in the room I3 could be maintained high by operatingthe apparatus as 'described above. Thus the apparatus o1' Figure 1 maybe adapted to condition air in various ways.

Another way of utilizing the principles of the invention to conditionair of a dwelling'house or the like is illustrated in Figure 2 in whichthe arrangement is such that not only the humidity but also thetemperature of the air may be changed.'

Referring to the arrangement of Figure 2 in detail it will be seen thata dwelling house is there indicated as havingv an east wall 30 and awest Wall 3|, these walls being shown in cross-section Y and beingconstructed of heat insulating matethrough opening 35.

'I'he chamber 32 is connected to the room vof the dwelling house by twodampers or doors, the

damper 31 being above the humidifying appa` ratus and opening into theroom,v and the-damper 38 being below the humidifying apparatus andopening into the chamber 32. Likewise the chamber 33 is provided withsimilarly arranged dempers 33 and 40.

Outside o1' the east wall 30 oi'I the dwelling house an absorbingchamber is formed as shown at 4| by means of the vertically extendingmetallic structure 42. 'I'his chamber contains a number of pans or traysas indicated at 43 adapted to contain calcium chloride or silica gel orother absorbing material, the arrangementr shown having a solution ofcalcium chloride on the upper three of the baille trays 43, with silicagel on the lower five of these trays. The use of two absorbents in eachchamber, which is one feature of the invention, permits absorption toahigh degree, because the absorbents will absorb the water vapor atdifferent partial pressures.

For heating the chamber 4l in addition to heat which may be conveyedthrough the wall 42 of the chamber from the sun, a chimney or heater lllis provided. This chimney also provides means for supportingv thebaiiieplates 65 which serve to direct air passing through the chamber il overthe al: sorbing substances on the trays t3. Below the chimney t@ ahorizontally extending passage All may be provided and this passage maycontain a gas heater, air for combustion being supplied to the heaterfrom the outside by any suitable means. This articial heating means neednot be used all the time, but may be used as desired.

The upper end of the chamber il may be connected to the atmosphere or toany air circulator such as a fan by means of the air conduit 8. mielower end of the chamber il is connected to the chamber 32 in the wall3d by means of an air passage i9 in the wall 3u.

The arrangement on the outside of the west `wall 3l o the house isexactly the same as that -on the veast side, a chamber 5i being formedby an outer metallic wall 52, the chamber 5i having a number of trays b3for supporting absorbing material. A chimney til is provided andsupports baie plates 55. The chimney Ml is heated by a heater in ahorizontally extending conduit 5l. The upper end of chamber 5i isconnected to the atmosphere or a fan (not shown) by pipe 53. The lowerend of the chamber 5l is connected to the chamber 33 in the wall 3l bymeans of the air passage 59 in the wall 3i.

I The conditioning of the room in the dwelling is eected preferablyautomatically by the sun. it

can, however, be eected artificially and perio'dically by alternatelyheating the chambers ll and 5i. Assuming that it is desired that theapparatus be used to lower the humidity or cool the air in the room andthat the apparatus is operated by the sun only, the operation is asfollows: in the morning the sun shines against the wall l2 on the eastside of the house and the contents of the chamber il are heated.Circulation of air is thus produced by' convection. II'he air entersthrough the conduit 58 on the west side of the house goes downwardlythrough the chamberbl, rises in the conduit 59, enters the room aftergoing through the chamber 33 and across the humidier therein, passesthrough the opening Aat the top of the chamber 33, the damper to beingclosed at this time. After flowing through the room the air flowsdownwardly through the conduit t@ in the wall 30, the damper 38 thenbeing open and enters the chamber Ill on the east side of the house,passes upwardly therethrough and leaves this chamber through the conduitt8. The west side of the house being cool and the east side warm duringthis portion of the cycle,

the humidity of the air in the chamber 5l is de# downwardly through thechamber 5i is lowered to such an extent that as it .passes into thechamber 33 it has a temperature of 35 degrees C. and a dew point of C.This air may be cooled to a temperature of 20 C. by contact with thewicking 36 in the chamber 33 while the dew point of the air is raised to14 C. By changing theposition of the shutters 39 and 40, the temperatureof the air entering the room can be raised and the dew point lowered.For example, if the lower shutter 40 is opened only a small amount theair in the room may assume a temperature of 25 C. while the dew pointbecomes about 10 C. In operating the apparatus of Figure 2, thedirection of air circulation is reversed periodically in synchronismwith the heating periods. Where convection alone is usedY to causecirculation of the air, the synchronism of air and heating periods isautomatic, the heating of chamber di causing circulationA of air in thedirection just described and the heating of chamber l causingcirculation in a reverse direction.

When operated by the sun, circulation of air eiected by convectionceases as the sun passes the meridian. In the afternoon when the sunshines upon the west side of the house so that the direction ofcirculation of air is reversed, the air enters the apparatus through theconduit d8, passes downwardly through the chamber @l and into the roomthrough the chamber 32 in the wall 33. In general, it should be saidthat during this portion of the cycle the damper 3l should be open anddamper 38 closed, while the damper v39 is closed and damper @il open.Air then leaves the room through the damper d, passes downwardly throughthe passage 59 and upwardly through the chamber 5|, leaving theapparatus through the conduit 58.

inasmuch as the absorbent material in chamber il became very dryduring,r the morning, due to the fact that it was heated, the air -nowentering the chamber 32 will be even dryer than that which enters thechamber 33 in the morning.

l'n the afternoon the air entering the room may be cooled by means ofthe humidifier 36 and its associated apparatus in the chamber 32 just asit was cooled by the'humidier in the chamber 33 in the morning.

It will be seen that when operated in this way the apparatus providesmeans for drying and cooling airsupplied to a room, and on warmsummerdays when the sun is shining the air may be conditioned by meansof the sun alone. It will also be sean that it is possible to aircondition a room without the use `of moving parts, the air beingcirculated through the room merely by convection currents. It is to beunderstood,.how ever, that. it is within the purview of the invention tocause the air to circulate in the directions indicated above byusingfans or blowers. It is also contemplated to promote circulation inthe desired direction under the pressures created by wind blowing aroundthe house, as for example, across the roof. The conduits i3 and 58 maybe connected to funnels or vents on the roof so positioned as to createthe desired draft through the house depending upon the direction andmagnitude of the wind. Due to the provision of the heaters il and 57 theapparatus can be operated without utilizing the heat of the sun and theperiod of heating or cooling of the chambers il and 5! can be varied asdesired.

It is also possible to use the apparatus of Figure 2 to raise thehumidity of air entering the room by causing the air to circulate in theopposite directions to those given above. Thus if the air is circulated,`by means of a fan or the like l the room, downwardly through passages32 andl 49 and upwardly through chamber 4i, while the invention to soconstruct the chambers iland 5l as to permit them to be slowly turned soas to face the .sun and thus operate at maximum eiciency.

It is also contemplated to place the conduits conveying air into and outof the room in heat exchange relation so as to increase theeffectiveness of the apparatus.

While the apparatus has been explained in connection with theconditioning of air, it is obvious that other inert gases could beconditioned thereby and absorbable constituents other than water removedtherefrom. n

Various other changes in the arrangement and construction oi parts maybe made without departing from the spirit of the invention or the scopeof the annexed claims. j

I claim:

l. Apparatus for conditioning the air in a room comprising two chambers,absorbent material in said chambers, means for conveying air through oneof said chambers, the room, and the other of said chambers, means f orperiodically reversing the direction of ow of the air comprlsing meansfor alternately heating said chambers to cause the absorbent in thechamber heated to give' up moisture to the air therein.

2. Apparatus for conditioning the air in a room comprising two chambers,absorbent ma.- terial in said chambers, means for conveying air throughone of said chambers, the room, and the otherof said chambers, means forperiodically reversing the direction of i'low of the air comprisingmeans for alternately heating said chambers to cause the absorbent inthe chamber heated to give up moisture to the air therein and means forcooling the air entering the room by causing water t0 evaporate into theair.

3. Intermittent absorption refrigerating apparatus comprising a rstabsorber-generator, a second absorber-generator, an evaporator, meansfor periodically causing an inert gas to ow first through the rstmentioned absorber-generator, the evaporator and the second mentionedabsorber-generator and then through the second mentionedabsorber-generator, the evaporator and the first mentionedabsorber-generator comprising means for heating each of saidabsorbergenerators only when the inert gas is owing through it afterhaving passed through the other absorber-generator and the evaporator.

4. The process of conditioning air Which consists in periodicallypassing the air over two separate bodies of absorbent material, first inone direction and then in thev other, maintaining the body over whichthe air first passes at a lower temperature than the other body therebycausing the body over which the airrst passes to remove moisture fromthe air and thereby causing ing means and so arranged that when one ofsaid absorber-generators is subjected to the heat of the sun the otheris shielded therefrom, and

having an opening in each of said absorber-gelierators near the endremote from said conveying meanasaid apparatus being characterized bythe fact that during part of the day air flows in one of said openings,through one of said absorber-generators, through said conveying meansand then through the other absorber-generator, and during another partof the day the air flows in the reverse direction, said reverse oW beingcaused by the reversal of said absorber-generators with respect to thesun, whereby air is dried as it passes through said shieldedabsorber-generator, and said heated absorber-generator is `reactivatedfor subsequent use as a drier.

6. Apparatus for conditioning air of the type employing twoabsorber-generators containing absorbent medium and one of which isperiodically subjected to the heat of the sun to reactivate theabsorbent while the other is shielded from the heat of the sun to permitwater vapor to be absorbed from atmospheric air, and in which means isprovided for delivering air discharged irom one absorber-generator tothe other, said absorber-generators being characterized by the fact thateach has an air inletso positioned that the heating of either onethereof will cause the air therein to rise and thereby cause air to flowfirst' through o ne absorber-generator, then through said air deliverymeans, and nally through the other absorber-generator.

7. Apparatus for conditioning air comprising a housing, independentabsorber-generators con-l taining absorbent medium positioned at oppo-vsite sides of said housing such that the sun may heat rst one and thenthe other thereof to drive off water vapor contained in said absorbentwhile one remains shielded from the heat of the sun to dry air passingtherethrough, air inlet means to each of said absorber-generators, meanswithin said housing for conducting air between said absorber-generators,and means operable to modify the condition of the air as it passesbetween said absorber-generators as the result of thermo-syphonic actioncaused by the heating of one of said absorber-generators by the sun.

8. The process of conditioning air which comprises passing a risingstream of air over absorbent medium heated by the sun to reduce themoisture content of the absorbent, conducting said flowing air streaminto an area shielded from the heat of the sun, modifying the absolutehumidity of the airV for a utilitarian purpose, then passing the airstream downwardly over absorbent medium shielded from the heat of thesun to dry the air, and periodically reversing the direction of air flowby subjecting said shielded absorber-generator to the heat of the sun.

9. The method of conditioning an enclosure which comprises passing' airovera rst body of absorbent to dry the air, cooling the air byevaporative cooling, conducting the cooled air to an enclosure, ventingthe air displaced by said cool air to the atmosphere after firstconducting the same over partially saturated absorbent heated by the sunto reactivate said absorbent, and then reversingv the direction of airflow by heating the moistened absorbent by solar energy while shieldingthe rst body of absorbent therefrom.

10. Apparatus for conditioning air consisting of two chambers and an airconducting means connecting the chambers, each chamber containing a bodyof absorbent material, each chamber having an opening permittingcommunication between such chamber and a point outside the apparatus,vand each chamber having a heating arsaesa means; thel arrangement beingsuch that when either chamber alone is heated air will pass in seriesthrough the other chamber, the air conducting means connecting thechambers, and

'finally through said chamber being heated.

ll. A structure comprising a building having a room to be conditioned,la, pair oi chambers communicating with said room and absorbent bodiesin each of said obers; each chber having a conduit for affordingcounicatlon between the same and the atmosphere outside said structureand each 1|; i 1:.. being positioned on the building to be shadedthereby from the heat of the sun when the other chamber is exposed tothe heat of the sun; the arrangement being such that vwhen one of theobers is heated by the'sun a circulation of will be promoted, in series,from the exterior of the building through the other chamber, said roomand said chamber heated by the sun.

l2. Apparatus for drying air comprising two inter-connected chambers,each of which contains absorbent material, an opening near the top ofeach of said chambers to the atmosphere, means i3. Apparatus for remomoisture from vairv comprising a rst s. m containing absorbent material,a second cber containing absorbent material, means connecting said c 1-ers to the atmosphere and a conduit connecting said chambers whereby airlmay dow through said chambers and conduit in either direction, meansfor exposing the nrst mentioned chamber to a source of heat whereby theair is caused to ow from the rst mentioned chamber to the secondmentioned chamber, means lfor exposing said second mentioned chamber toa source of heat after discontinuing the heating of the rst char wherebythe air iscaused to iiow from the secon mentioned chamber' to the rstmentioned l1 ber, the 4arrangement being such 'that the absorbentmaterial gives up moisture to the air whenthe chamber in which it islocated is heated, and removes Amoisture from the air when the chamberin which it is located is not heated Vto be exposed to the heat of thesun in the afternoon, Vsaid chambers containing independent charges ofabsorbent material, and means for conveying air periodically in oppositedirections n through iir'st one Volf said chambers, said room, and thenthrough the other of said chambers.

15.-'I'he process of conditioning air which comp passing the air overtwo separate bodies oi absorbent material periodically, rst in onedirection, and then in the opposite direction by alternately heating oneof said/bodies above the temperature of the other, the process beingsuch that the absorbent bodies are automatically caused to alternatelygive up moisture to the A air synchronously with the periodic ow of theair, the moisture so given up being moisture which has been absorbedfrom. the air by one of the bodies when that body was not being heated.

i6. The method of conditioning air which comprises drying one portion ofa stream of air for a useful purpose by passing it over absorbentmaterial shielded from the heat of the sun during the forenoon, whichabsorbent material has body of absorbent material, and then another bodythereof, one of said bodies being subject to the heat of the sun and theother being shielded therefrom during part of the day, and the positionof said bodies with respect to the sun being reversed during anotherpart of the day, whereby the air passing over said shielded body ofabsorbent is dried for a' useful purpose, .and the other body ofabsorbent material being heated bythe sun is being simultaneouslyreactivated foruse later in drying other air.

18. Apparatus for conditioning air of the type employing twoabsorber-generators containing absorbent mediums and connected by iluidconveying means including a chamber to be lcondi`4 tioned for conductingair in series therethrough, said apparatus requiring only a source ofheat to energize and operate the same and being constructed and arrangedto condition atmospheric air at atmospheric pressure, and toautomatically cause flow of the air being conditioned therethrough bythermo-syphonic action, said apparatus being characterized by the factthat when one absorber-generator is being heated 4by a source of heatthe other is shielded therefrom,

19. Apparatus ior conditioning air of the type employing twoabsorber-generators containing independent absorbent charges and one ofwhich is alternately subjected to the heat of the sun for a period oftime to reactivate the absorbent while the other is shielded from theheat of the sun for a period of time to permit water vapor to beabsorbed from atmospheric air, and thereafter said absorber-generatorsare reversed with respect to the heat of the sun, said vapparatus beingcharacterized by the fact that the dried air delivered by oneL of saidabsorber-generators is conducted to a point of use which is heatinsulated from both of said absorber-generators, the air beingsubsequently returned to the other absorber-generator for use inreactivating said` last named absorber-generator.

